1b12 Group Actors

I'd like to recommend that Ghost update the main index actor to be as:Group type, adhering to FEP 1b12.

The properties on both types are equivalent, both have public keys, etc.

The changes would be:

• Instead of federating Create(Article) directly, you would Announce(Create(Article)) and Announce(Article) (for Mastodon compatibility)
• The Create's actor and the Note's attributedTo would be the actual post author
  • This would of course hinge on the future support for multiple AP authors

Rationale:

Threaded implementations could slot all content published by the blog itself in an organized collection (like a forum category).

Prior art:

Lemmy/Mbin/NodeBB all do this with their communities/categories. WordPress also does this.

• @pfefferle's blog: https://notiz.blog/
• On the fediverse: https://browser.pub/notiz.blog@notiz.blog
• as viewed from NodeBB: https://community.nodebb.org/category/notiz.blog@notiz.blog

Start by tracing how Ghost exposes its main index actor and federates Create(Article) and Article activities. Review the FEP 1b12 requirements and the issue's Mastodon compatibility notes, including the dependency on multiple ActivityPub authors. Done means the index actor is represented as as:Group and the described Announce and author attribution behavior works compatibly.